Weekly digest #94: price changes in copper

Copper Is Moving Again

Copper spot closed near $4.85/lb this week, up roughly 12% over the last 30 days. Supply disruptions out of Chile and stronger demand from grid-scale battery projects are the main drivers. If you quoted jobs in March at $4.30, your material line is already underwater.

Every spool of THHN, every length of SER, every pound of bare ground wire just got more expensive. Distributors are repricing daily, not weekly. Some branches are holding quotes for 24 hours only. Check before you pull from the rack.

This matters most on service upgrades, feeder runs, and parallel sets. A 400A residential service with parallel 3/0 copper feeders can swing $600 to $900 on wire alone compared to a quote written six weeks ago.

Requote Open Bids Before You Lose Margin

Go through your open proposals. Anything dated more than two weeks back needs a fresh look at the copper line items. Most commercial GCs understand material escalation clauses, but residential customers often do not. Have the conversation before the wire shows up on site.

If your proposals do not already include an escalation clause, add one now. Something simple: material prices are valid for 15 days from proposal date, subject to current distributor pricing thereafter.

• Pull all proposals over 14 days old
• Check current distributor pricing on every copper SKU
• Flag jobs where copper is more than 20% of total material
• Call the customer before they call you
• Update your template proposal to include escalation language

When Aluminum Starts Making Sense

At these copper prices, aluminum feeders become the default conversation for any run over 100 feet at 200A or larger. The ampacity tables in NEC 310.16 let you upsize aluminum to match copper ampacity, and the cost delta often pays for the larger conduit and lugs twice over.

Service entrance conductors are the easy win. A 4/0 aluminum SER for a 200A residential service versus 2/0 copper saves hundreds per service. Just verify your panel lugs are listed for aluminum per NEC 110.14, and use the right antioxidant compound on terminations.

Aluminum is not the problem. Bad terminations are the problem. Torque every lug to spec with a calibrated wrench, apply listed compound where required, and retorque after the first load cycle if the manufacturer calls for it.

Remember NEC 310.10(H) for parallel conductors: if you go aluminum, all conductors in the parallel set must be aluminum, same length, same terminations. No mixing.

Voltage Drop Math Changes the Picture

NEC 210.19 Informational Note 4 recommends a 3% voltage drop for branch circuits and 5% combined for feeder plus branch. This is not mandatory in most installs, but it is where aluminum versus copper gets interesting on long runs.

Aluminum has about 61% the conductivity of copper, which means you typically upsize one or two trade sizes to hit the same voltage drop target. On a 150 foot feeder at 200A, 4/0 copper gets you there. Aluminum needs 250 kcmil or 300 kcmil depending on load factor.

Run the numbers both ways for anything long. Copper at current prices can still win on short runs where the wire cost is small relative to labor and conduit. Aluminum usually wins past 75 feet on anything 100A or larger.

1. Calculate load at terminal end
2. Measure one-way distance accurately
3. Target 3% for branch, 5% total for feeder plus branch
4. Compare copper and aluminum sizes meeting the target
5. Price both at current distributor rates

Protect Your Copper on Site

Copper theft tracks copper prices. When spot goes up, jobsite losses go up. Rooftop units, temporary service conductors, and reels left in gang boxes are the common targets. A single stolen spool of 500 MCM can run north of $2,000 at today's prices.

Lock up reels at end of shift. Do not leave cut lengths of bare copper ground on the ground overnight. On rough-in, pull what you will install that day, not what you might install this week.

If you are running temporary service for a framing crew, use aluminum SER where code allows. It is cheaper to replace, and nobody is driving off with it in the middle of the night.

Watch the Distributor Game

In volatile markets, distributors play the float. Some will hold old pricing for good customers, some will reprice everything Monday morning. Build relationships with two or three branches and know which one is which.

Ask for pricing in writing with a validity date on it. A verbal quote at the counter means nothing when you come back Thursday to pick up the wire. Email quotes with timestamps save arguments.

If you buy in volume, this is the time to lock in a standing price agreement for the next 30 to 60 days. Distributors who want your repeat business will work with you. The ones who will not are telling you something about the relationship.